A strange musical being from whom no high-concept conceit should come as a surprise, Björk returns with an album made almost entirely with the human voice. It's both more and less unusual than it sounds: On the surface, Medulla swoops and hums like a typical Björk album, showcasing her spastic and solemn sides in dramatic songs that suck up all the air around them. The denser tracks feature swaths of voices in unorthodox settings—odd choral chants, human-beatbox drum lines, nasal noise riffs—but they basically mimic the avant-pop backings that first made Björk a futuristic throwback to crooner-era swing, Bollywood soundtracks, hyperactive jungle, and fidgety glitch electronica.
Once its novelty factor fades, Medulla settles down as a stirring, nuanced album that takes a while to take hold. A few pop songs ("Who Is It," "Triumph Of A Heart") shout out for notice, but more common are pensive mood pieces that sound more like studies than songs. "Pleasure Is All Mine" opens with Björk wide-eyed beside an ancient-sounding swirl tended by The Icelandic Choir, hip-hop beatboxer Rahzel, Inuit throat singer Tagaq, and art-rock spaz Mike Patton. The gnostic spin carries through most of the record, but no amount of somberness can keep Björk tethered for long: By "Who Is It," she's soaring over the mouthy simulation of a buoyant dance track, swallowing her words and gargling their connotations in search of answers to questions that focus on everything and nothing. In "Desired Constellation," she throws a "palm full of stars… like dice" over a gorgeous glitch field. The electronic flourish strays from her organic vocal focus, but Björk summons the same kind of tingle with choral language in "Oceania," which finds The London Choir reacting to what sounds like a thrilling slow-motion circus act.
Some of Medulla's most striking moments play out in small scale: the stunning "Submarine" features little more than Björk and English rock shaman Robert Wyatt in interlocking harmonic moans, while "Ancestors" plays with a smatter of grunting goblin sounds and emotive whimpers. Sure to rankle those with even the slightest aversion to Björk's prim fancies, Medulla shows the singer in her weirdest and least immediately rewarding form yet. Once perceptions and expectations settle out, however, the album proves arrestingly in thrall to its own twisted tongue.